| Environments | PYTHON :: EASI :: MODELER |
| Batch Mode | Yes |
| Quick links | Description :: Parameters :: Parameter descriptions :: Details :: Related |
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| Name | Type | Length | Value range |
|---|---|---|---|
| InputNumer: Input channels for ratio numerator * | Raster port | 1 - 16 | -1024 - |
| Weight List for Ratio Numerator | Float | 0 - 16 | Default: 1.0 |
| Constant for Ratio Numerator | Float | 0 - 1 | Default: 0.0 |
| InputDenom: Input channels for ratio denominator | Raster port | 0 - 16 | -1024 - |
| Weight List for Ratio Denominator | Float | 0 - 16 | Default: 1.0 |
| Constant for Ratio Denominator | Float | 0 - 1 | Default: 0.0 |
| Output: Output raster channel | Raster port | 0 - 1 | |
| Port Settings: Resample mode | Raster port | 1 - 1024 | Nearest | Bilinear | Cubic Default: Nearest |
| Output Raster Type: Output channel type * | Raster port | 1 - 1 | 8U | 16S | 16U | 32R |
| Scaling Mode | String | 4 - 1 | NONE | AUTO | LOGS Default: NONE |
| Area Mask: Area mask | Bitmap port | 0 - 4 | |
| Value for Division by Zero | Float | 0 - 1 |
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InputNumer: Input channels for ratio numerator
Specifies the input image channels that will be added together to form the ratio numerator.
Up to 16 channels can be specified; at least one must be specified. Duplicate channels are NOT allowed.
Weight List for Ratio Numerator
Optionally specifies the weights to be assigned to channels listed in the numerator.
The weights correspond to the input channels listed in CNUM (InputNumer) by their position in the list.
Constant for Ratio Numerator
Optionally specifies a REAL constant to be added to the numerator.
InputDenom: Input channels for ratio denominator
Optionally specifies the image channels (up to 16) to be added together to form the ratio denominator.
Up to 16 channels can be specified. Duplicate channels are NOT allowed.
Weight List for Ratio Denominator
Optionally specifies weights to be assigned to channels listed in the denominator.
The weights correspond to the input channels listed in CDEN (InputDenom) by their position in the list.
Constant for Ratio Denominator
Optionally specifies a REAL constant to be added to the denominator.
Output: Output raster channel
Specifies the output channel to receive the ratioed image.
if output to the new file , this parameter is ignored.
When your output file is a new file; that is, it does not exist already, you need not specify a value for this parameter; channel in the new file will be of the bit depth specified by the value of the DATATYPE parameter.
Port Settings: Resample mode
Specifies the type of image resampling desired.
Output Raster Type: Output channel type
Specifies the image data type of the output raster channel.
Scaling Mode
Specifies the scaling mode.
If the specified output channel (DBOC) is 32-bit real, this parameter is ignored. See Scaling in the Details section for more information.
Area Mask: Area mask
Specifies the bitmap that defines the area to be processed within the input raster.
If no value is specified, the entire channel is processed.
Value for Division by Zero
Specifies the value to use for the result of a denominator equal to zero.
If this parameter is not specified, this value defaults to the maximum possible value for the specified output channel.
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RTR calculates any pixel by pixel ratioing transformation of the following form:
WNUM(1)*CNUM(1) + WNUM(2)*CNUM(2) + ... + WNUM(i)*CNUM(i) + NCON ---------------------------------------------------------------- WDEN(1)*CDEN(1) + WDEN(2)*CDEN(2) + ... + WDEN(i)*CDEN(i) + DCON
If weights (WNUM, WDEN) are not specified, they default to 1.0. If constants (NCON,DCON) are not specified, they default to 0. If denominator channels (CDEN) are not specified, the constant for ratio denominator defaults to 1.0.
Results of this function are saved to the specified output channel (DBOC).
The MASK parameter specifies the area within the input channel to be processed. Only the area specified under the mask is processed; the rest of the image is unchanged.
Calculations are performed using real arithmetic. If the specified output channel is 8- or 16-bit, some loss of accuracy will occur. To help mitigate this, you can specify scaling options (SMOD).
Scaling
RTR performs ratioing transformation on 8-bit unsigned integer, 16-bit signed integer, 16-bit unsigned integer, and 32-bit real channels. These channels have the following ranges for data:
Type Min Max 8-bit unsigned integer 0 255 16-bit signed integer -32768 32767 16-bit unsigned integer 0 65535 32-bit real 1.0E38 +1.0E38
NONE: no scaling is performed. If the resulting value is less or more than the output channel can hold, it will be set to the minimum or maximum, respectively, that the channel type can hold. This option is most commonly used if the output channel is 32-bit real.
AUTO: linear scaling is performed. This is accomplished by performing two passes on the data. The first pass is used to determine the minimum and maximum values resulting from the ratioing transformation. In the second pass, these values are used to linearly scale the results to the full range of the output channel.
LOGS: logarithmic scaling is performed. This is accomplished by performing two passes on the data. The first pass is used to determine the minimum and maximum values resulting from the ratioing transformation. In the second pass, these values are used to logarithmically scale the results to the full range of the output channel.
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